Slot antenna

Abstract

Technology is described for a slot antenna. The slot antenna can include a substrate having a metal layer on a first side of the substrate. A feed line can be located on a second side of the substrate. A first polygon shaped slot can be formed in the metal layer of a first side of the substrate. A second polygon shaped slot can also be formed in the metal layer of the first side of the substrate. The second polygon shaped slot can be recessed within a perimeter of the first polygon shaped slot and the second polygon shaped slot and first polygon shaped slot share a common side. Examples of the first and second polygon shapes may include square or diamond shapes.

1. A slot antenna, comprising:
 a substrate having a first side and a second side and a metal layer on the first side of the substrate; 
 a feed line on the second side of the substrate; 
 a first polygon shaped slot formed in the metal layer of the first side of the substrate; and 
 a second polygon shaped slot formed in the metal layer of the first side of the substrate, wherein the second polygon shaped slot is recessed within the first polygon shaped slot, and wherein the second polygon shaped slot and the first polygon shaped slot share a common side. 
 
     
     
       2. The slot antenna as in  claim 1 , wherein the second polygon shaped slot and the first polygon shaped slot share two sides of a polygon shape forming a portion of an outer slot. 
     
     
       3. The slot antenna as in  claim 1 , wherein the feed line is further oriented at an angle perpendicular to a side of the first polygon shaped slot. 
     
     
       4. The slot antenna as in  claim 1 , wherein the first polygon shaped slot and the second polygon shaped slot are oriented at an angle with respect to an edge of the substrate. 
     
     
       5. The slot antenna as in  claim 1 , wherein the first polygon shaped slot and the second polygon shaped slot are oriented at a 45 degree angle with respect to an edge of the substrate. 
     
     
       6. The slot antenna as in  claim 1 , wherein the feed line further comprises two feed lines. 
     
     
       7. The slot antenna as in  claim 6 , wherein a first feed line is oriented perpendicular to a first side of the first polygon shaped slot and a second feed line is oriented perpendicular to a second side of the first polygon shaped slot. 
     
     
       8. The slot antenna as in  claim 6 , wherein the two feed lines allow two polarizations to be excited independently. 
     
     
       9. The slot antenna as in  claim 8 , further comprising a feed switching circuitry that enables switching between the two feed lines to create the two polarizations. 
     
     
       10. The slot antenna as in  claim 1 , wherein the second polygon shaped slot has a central region and the feed line crosses into the central region. 
     
     
       11. The slot antenna as in  claim 1 , wherein a gap distance between the first polygon shaped slot and the second polygon shaped slot is sized to provide a higher and lower frequency resonance. 
     
     
       12. The slot antenna as in  claim 1 , wherein the substrate is a printed circuit board. 
     
     
       13. A slot antenna, comprising:
 a substrate having a first side and second side; 
 a metal layer on the first side of the substrate; 
 a first polygon shaped slot formed in the metal layer of the first side of the substrate; 
 a second polygon shaped slot formed in the metal layer of the first side of the substrate, wherein the second polygon shaped slot is recessed within a perimeter of the first polygon shaped slot and the second polygon shaped slot and first polygon shaped slot share two common slot sides; 
 a first feed line on the second side of the substrate that is oriented perpendicular to a side of the first polygon shaped slot; and 
 a second feed line on the second side of the substrate that is perpendicular to a second side of the first polygon shaped slot. 
 
     
     
       14. The slot antenna as in  claim 13 , wherein the first polygon shaped slot and the second polygon shaped slot are oriented at a 45 degree angle with respect to an edge of the substrate. 
     
     
       15. The slot antenna as in  claim 13 , wherein the first feed line and the second feed line allow two polarizations to be excited independently. 
     
     
       16. The slot antenna as in  claim 15 , further comprising feed circuitry that enables switching between the first feed line and the second feed line to create the two polarizations. 
     
     
       17. The slot antenna as in  claim 13 , wherein the second polygon shaped slot has a central region and the first feed line and the second feed line cross into the central region. 
     
     
       18. The slot antenna as in  claim 13 , wherein a gap distance between the first polygon shaped slot and the second polygon shaped slot is provided so as to provide a higher and lower frequency resonance. 
     
     
       19. A method for making a slot antenna, comprising:
 applying a metal layer to a first side of a substrate; 
 forming a first polygon shaped slot in the metal layer of the first side of the substrate; 
 forming a second polygon shaped slot in the metal layer of the first side of the substrate, the second polygon shaped slot being recessed within a perimeter of the first polygon shaped slot, wherein the second polygon shaped slot and the first polygon shaped slot share two common slot sides; and 
 applying a metal trace to a second side of the substrate to form a feed line oriented perpendicular to a side of the first polygon shaped slot. 
 
     
     
       20. The method as in  claim 19 , further comprising applying a second feed line on the second side of the substrate that is perpendicular to a second side of the first polygon shaped slot.